self& operator++()
Pre-increment.
Move the iterator one element backward, so that the element it sits on has a bigger index. Use ++iter rather than iter++ where possible to avoid two useless iterator copy constructions.
self operator++(int)
Post-increment.
Move the iterator one element backward, so that the element it sits on has a bigger index. Use ++iter rather than iter++ where possible to avoid two useless iterator copy constructions.
When we talk about iterator movement, we think the container is a uni-directional range, represented by [begin, end), and this is true no matter we are using iterators or reverse iterators.
When an iterator is moved closer to "begin", we say it is moved forward, otherwise we say it is moved backward.